Antioxidative effects of Alisma orientale extract in palmitate-induced cellular injury.

CONTEXT: Alisma orientale (Sam.) Juzepczuk (Alismataceae) is an indigenous medicinal herb that has been traditionally used for diuretic, hypolipidemic, anti-inflammatory, and antidiabetic proposes in northern and eastern Asia.

OBJECTIVE

This study examined the mechanisms underlying the cytoprotective effect of an aqueous extract of A. orientale (AEAO) against long-chain saturated fatty acid-induced cellular injury.

MATERIALS AND

METHODS

HepG2 cells were treated with 0.5 mM palmitate to generate a cellular model of nonalcoholic fatty liver disease (NAFLD). Using this cellular model, the cytoprotective effect of AEAO (100 µg/mL) against long-chain saturated fatty acid-induced cellular injury was evaluated by measuring the steatosis, ROS accumulation, and apoptosis.

RESULTS

AEAO significantly attenuated palmitate-induced intracellular steatosis and cellular damage up to 54 and 33%, respectively. Palmitate-induced intracellular levels of reactive oxygen species (ROS) and reactive aldehydes were significantly reduced in the presence of AEAO to 40 and 75%, respectively, suggesting that oxidative stress plays a role in the palmitate-induced damage. AEAO inhibited the palmitate-mediated activation of c-Jun NH(2)-terminal kinase (JNK), a kinase that is correlated with NAFLD. Inhibition of JNK by SP600125 or addition of AEAO significantly reduced palmitate-induced steatosis, ROS accumulation, and apoptosis, indicating that the protective effects of AEAO against palmitate-induced cellular damage result from blocking ROS-activated JNK signaling.

DISCUSSION AND

CONCLUSION

The combined properties of AEAO in cellular steatosis and ROS production are beneficial for treating NAFLD, which includes complex metabolic changes, such that modulation of a single target is often not sufficient to achieve the desired therapeutic effect.